iPad review by David Pogue of The New York Times

Quote from the article “Speaking of video: Apple asserts that the iPad runs 10 hours on a charge of its non-removable battery â€” but we all know you canâ€™t trust the manufacturer. And sure enough, in my own test, the iPad played movies continuously from 7:30 a.m. to 7:53 p.m. â€” more than 12 hours. Thatâ€™s four times as long as a typical laptop or portable DVD player.”